In a processing apparatus such as a pulverizer or a reactor, there are some cases where a target substance comprising a strong acid such as hydrochloric acid or sulfuric acid is treated under an acidic corrosive environment. A treatment container for containing such a target substance is fabricated by subjecting general steel materials to welding. For this reason, an inner wall of the treatment container is likely to be damaged due to not only abrasive wear but also corrosion by the target substance. It is therefore desired to provide an inner wall (welding member) having corrosion resistance and abrasion resistance.
Meanwhile, the following Patent Document 1 discloses a deposited metal produced by build-up welding (overlay welding), wherein it has oxidation resistance and abrasion resistance and exhibits high hardness, at a temperature of 600° C. or more. The deposited metal comprises C: 0.5 to 3.0%, Si: 3.0 to 7.0%, Cr: 25 to 45%; Mn: 0 to 10% and Ni: 0 to 13%, wherein the following relation is satisfied: Cr≧−1.6 Si+37, and the balance of the composition consists of Fe and unavoidable impurities, and wherein the deposited metal has a metal microstructure in which short fiber-shaped carbide pieces are precipitated finely and in large numbers. The Patent Document 1 also discloses a build-up welding material for forming the deposited metal. The build-up welding material comprises C: 0.5 to 3.0%, Si: 3.0 to 7.0%, Cr: 25 to 45%; Mn: 0 to 10% and Ni: 0 to 13%, wherein the following relation is satisfied: Cr≧−1.6 Si+37, and the balance of the composition consists of Fe and unavoidable impurities.